POWER SUPPLY CONTROL IN A WIRELESS RECEIVER

• US 20100322228A1
• Filed: 01/28/2009
• Published: 12/23/2010
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Neuteboom, Harry, Noel, Denis, Aerts, Steven
• Granted Patent: US 9,319,984 B2
• Time in Patent Office: Days
• US Class Current: 370/345
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 5/02 using transceiver
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless receiver is activated periodically to measure the level of received signals. It measures the average received level over a plurality of the activation periods, and enables the supply of power to receiver circuitry dependent on the measured average value. In one embodiment the power is enabled if an increase in the average value is detected which is greater than a predetermined margin. The average value may be measured in a sliding or stepped window. In another embodiment the power is enabled if the level in an activation period exceeds the average value by a predetermined margin.

Claims

1. A method of operating a wireless receiver, comprising:

measuring a level of energy received in each of a plurality of intermittent time periods;

generating a first value dependent on levels of energy in a first plurality of the time periods; and

enabling, dependent on the first value, a supply of power to a circuit.

2. A method as claimed in claim 1, further comprising:

generating a second value dependent on the levels of energy in a second plurality of the time periods, the second plurality including at least one time period occurring later than the time periods of the first plurality; and

enabling the supply of power if the second value exceeds the first value by more than a first margin.

3. A method as claimed in claim 2, wherein at least one of the time periods is common to the first plurality of time periods and the second plurality of time periods.

4. A method as claimed in claim 1, further comprising enabling the supply of power if the level of energy in at least one of the time periods exceeds the first value by more than a second margin.

5. A method as claimed in claim 1, further comprising generating at least one of the first value and the second value according to a recursive function of the levels of energy in the respective plurality of time periods.

6. A method as claimed in claim 1, further comprising generating at least one of the first value and the second value according to a function A_n=(1−

α

)A_n-1+α

·

E_n, where A_n is a value generated for an n^th time period, E_n is a level of energy in the n^th time period, and α

is a constant less than unity.

16. A computer-readable storage medium having a computer program adapted to perform the method of claim 1.

7. A wireless receiver, comprising:

a measurement circuit for measuring a level of energy received in each of a plurality of intermittent time periods;

an evaluation circuit for generating a first value dependent on levels of energy in a first plurality of the time periods; and

a controller for enabling, dependent on the first value, a supply of power to a circuit.

8. A wireless receiver as claimed in claim 7,

wherein the evaluation circuit is adapted to generate a second value dependent on the levels of energy in a second plurality of the time periods, the second plurality including at least one time period occurring later than the time periods of the first plurality;

and

wherein the controller is adapted to enable the supply of power if the second value exceeds the first value by more than a first margin.

9. A wireless receiver as claimed in claim 8, wherein at least one of the time periods is common to the first plurality of time periods and the second plurality of time periods.

10. A wireless receiver (300) as claimed in claim 7, wherein the controller is adapted to enable the supply of power if the level of energy in at least one of the time periods exceeds the first value by more than a second margin.

11. A wireless receiver as claimed claim 7, wherein the evaluation circuit is adapted to generate at least one of the first value and the second value according to a recursive function of the levels of energy in the respective plurality of time periods.

12. A wireless receiver as claimed in claim 7, wherein the evaluation circuit is adapted to generate at least one of the first value and the second value according to a function A_n=(1−

α

)A_n-1+α

·

E_n, where A_n is a value generated for an n^th time period, E_n is a level of energy in the n^th time period, and α

is a constant less than unity.

13. A wireless receiver as claimed in claim 7, wherein the wireless receiver is a magnetic induction receiver.

14. A wireless transceiver comprising the wireless receiver of claim 7.

15. A wireless system comprising the wireless receiver of claim 7.